Search for dissertations about: "oxyhydride"

Showing result 1 - 5 of 10 swedish dissertations containing the word oxyhydride.

2. 1. Dynamical properties of metal halide and oxyhydride perovskites

   Author : Rasmus Lavén; Chalmers tekniska högskola; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; perovskite; quasielastic neutron scattering; phonon; inelastic neutron scattering; diffusion; oxyhydride; hydrogen dynamics; Metal halide perovskite; hydride ion.;

   Abstract : This thesis concerns investigations on the dynamical properties of two classes of energy-relevant materials, namely metal halide and oxyhydride perovskites, using neutron scattering techniques. These two classes of materials share the same aspect of a perovskite-type crystal structure but are different in terms of their functional properties and concomitant promise for various technological applications. READ MORE

4. 2. Vibrational and Structural Characterisation in Two Perovskite Challenges: A Density Functional Theory Study

   Author : Erik Jedvik Granhed; Chalmers tekniska högskola; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; phonon; chemical expansion; materials modelling; oxyhydride; polaron; vibrational analysis; BaTiO3; BaZrO3; anti-ferrodistortive; density functional theory;

   Abstract : The modelling of perovskites using density functional theory (DFT) can sometimes be a challenge with many different states very close in energy. In particular, the tilting of the inscribed octahedron, as well as the formation of electron polarons, leads to states with energy differences in the meV range. READ MORE

5. 3. On hydrogen point defects in perovskite oxides

   Author : Erik Jedvik Granhed; Chalmers tekniska högskola; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; density functional theory; oxyhydride; phonon; point defects; chemical expansion; polaron; BaZrO3; proton conductor; BaTiO3;

   Abstract : Oxides based on the perovskite structure exhibit a surprisingly large diversity in materials properties and are found in many different applications, several related to clean energy technologies, such as solar cells, batteries and fuel cells. Many properties in materials are the result of lattice imperfections, commonly denoted \emph{defects}, and much effort is devoted to fine tuning materials properties through controlling the defects therein. READ MORE

6. 4. Structure-dynamics relationships in perovskite oxyhydrides and alkali silanides

   Author : Carin Eklöf-Österberg; Chalmers tekniska högskola; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; hydrogen storage material; long range diffusion; oxyhydride; neutron scattering; localized motion; hydride ion conduction; hydrogen dynamics;

   Abstract : This thesis focuses on investigations of the local structure and dynamics of two classes of hydrogen-containing, energy relevant, materials; perovskite type oxyhydrides BaTiO3-xHx and alkali silanides ASiH3 (A = K and Rb). In the area of oxyhydrides, which are of relevance for the development of electrolytes in fuel cells and batteries, the aim is to elucidate the dynamics and electronic character of the hydrogen species in the materials. READ MORE

7. 5. Mechanistic aspects of structure and dynamics in perovskite type oxyhydrides and alkali silanides

   Author : Carin Österberg; Chalmers tekniska högskola; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; inelastic neutron scattering; hydrogen dynamics; mean square displacement; quasielastic neutron scattering; localized motion; oxyhydride; energy materials;

   Abstract : This Thesis concerns experimental studies of the two alkali silanides ASiH3 (A = K and Rb) and the recently discovered perovskite type oxyhydrides BaTiO3-xHx (x = 0.14 and 0.40). READ MORE